Proper function of a steam turbine in a thermal power plant requires a shaft-sealed steam system and a drainage system.
The shaft-sealed steam system has the object of preventing air ingress into the steam turbine and also steam egress from the steam turbine into a power house. For that reason, air and steam are drawn out of the shaft-sealed steam system in a controlled manner. The air-steam mixture aspirated in that context, termed vapor steam, is conveyed to a vapor steam condenser. There, the steam fraction of the vapor steam condenses. The resulting condensate is conveyed to a main condenser of the thermal power plant. The air is conducted into the atmosphere. Atmosphere primarily refers to the air being discharged into a region in which approximately atmospheric pressure prevails. This can for example be a power house of the thermal power plant. In order to be able to better integrate the vapor steam condenser into a cooling circuit of the thermal power plant, the vapor steam condenser is configured for the available quantity of cooling water.
The drainage system serves for discharging water that accumulates in the steam turbine. This water still contains steam which must either be removed from the water or condensed. At this point, it should be noted that, in the context of this application and unless otherwise stated, water is to be understood as liquid water and steam as water steam.